Pyrotechnic composition



Patented Aug. 27, 1935 I re v 4 Claims. .,,This invention relates to, apyrotechniccome position designed'to be employed in the manuf a rareearth metalor an element of periodic facture of fireworks generallyfiinfwhich the object is' to obtaina spectacular fiare'or flash, with orwithout a detonative report, with a selective color range .for theflash, and if desired, with theeifusion of scintillating sparks or starsinto thefield of the flash.

The broad concept of the invention is the group IVa such'forexample' as,zirconium, or an alloyof the same is burned in mixture with a suitableoxidizing agent.

It isoldin the art-to employ a compound of group IVa as an oxidant inmixture with some other combustible as a fuel, but since zirconium andothers of the above indicated elements have ""a luminosity when burnedfar morebrilliant than substances heretofore used for a similarpurpose,.it is obvious that the gist of the present invention lies inthe fact of one of these substances or alloys of the same being used asthe fuel and not as-the oxidant.

Whether the combustion shall take the form of a flare or a flash dependsupon the selection of the oxidant. Color may in a few instances be ,anattribute of the oxidant, but in general it is obtained by the additionto the mixture of a specific color producing ingredient. Detonationlected from the group exemplified by, zirconium,

- a is employed in a comminuted state.

titanium, thorium, yttrium and selenium, and

It is characteristic of these elements and of their alloys that theyburn with an exceptionally brilliant flame, that they enhance thecombustive or fulminative sensitivity of the oxidizing agents with whichthey may be used in mixture, and that the sensitivity of the mixturedepends not only on'the inherent nature of the oxidant, but also uponthe'quantity ratio of the rare earth metal or its alloy to the oxidant.

Taking zirconium for example, one part of 3 this rare earth metal mixedwith three parts of 5 an oxidizing agent, such for instance, as bariumnitrate, makes a flash mixture which explodes when ignited by a fuse,butwhich is not sufliciently sensitive to explode by impact. Byincreasing the ratio of the zirconium to N two parts to three, relativeto the oxidant, a mixture is produced which readily explodes by impact.The sensitivity control afforded by vary: ing the proportions of therare earth metal or alloy relative to the oxidizing agent rendersavailable a number of oxidizing agents of diiferent co-efiicients ofsensitivity, such for example, as potassimn nitrate, barium nitrate,oxalates, trinitro compounds, chlorates and perchlorates. The oxidizingagent is selected according to the use to which it is to be put. If thepy otechnic device is of the type which is to be exploded, by impact,the oxidant is chosen with a View to giving the mixture a criticalfulminative sensitivity, the detonating point of which can be verydelicately determined by adjusting the quantity ratio of the oxidant tothe detonative ingredient or alloy.

For example, by using a mixture of zirconium, two parts and bariumnitrate, three parts, the exact proportions being adjusted to controlthe detonating point, a torpedo can be made so critical as to itsfulminative sensitivity as to be altogether safe with respect to theshocks incident to its manufacture and transportation, and which willexplode reliably under impact blows of a definite value above that ofthe incidental shocks referred to.

Where a particular color of the flash or flare is a desideration, anoxidant is chosen which will 40 produce a basic white color in the flameso that the imposed color will not be contaminated. For this purpose,the perchlorates are particularly suitable, for they not only burn thedetonative ingredients with a white colorless flame which does notimpair the purity of the imposed color,

but they release a greater volume of gas, thus extending the field ofthe flash.

One of the important characteristics of the pyrotechnic composition ofthe present invention wn-c Zirconium Perchlorates Strontium carbonate.

flash or The last named ingredient gives a red color to the flash. Thefirst two factors mixed in ratio of one to two give a mixture ignitibleby a fuse, and in the ratio of two to three a mixture fulmlnating byimpact.

For producing stars or scintillating sparks in the field of fiash, thedetonative ingredient is ground coarser than when intended for.instantaneous combustion. Thelarger granules do not consume immediatelybut are thrown out as highly incandescent burning particles or "stars.

' Each of the elements has a spark of characteristic visual appearance.The zirconium spark for example, appears as an amoeba-shapedstar, whichshape is modified in alloys of zirconium. The

characteristic sparks from burning. iron appear as" having thinradiating points.. In, a ferrous zirconium'alloy, the shape of the sparkis a, com.- promise between the zirconium and the 'iron sparks, the areaofthe amoeba shaped star characteristic of Zirconium being smaller, andthe radiating points being thinner and more deeply V indenting thecentral area.

A composition which'includes in the mixture,

several of the detonative ingredients exhibits an interesting varietyof, incandescent spark forms.

It is obvious from the above description that the new pyrotechniccomposition ,is not confined mixture.

to any single field of application in the art of pyrotechnics, but thatit is applicable to devices,

in which the composition isburned openly, without detonative eflfects,as in sparklers; in salutes which are ignited by a fuse, or in devicesexplod:

ing upon impact, such as torpedoes; What we claim is:

1. Pyrotechnic composition comprising a mix- Y ture of zirconium; and aperchlorate in proportion to detonate when confined, and a. colorimparting ingredient, the latter being present in such proportion as togive a decided colorto the flash yeventuating fromthe detonation of suchmix- 7 ture, the perchlorate functioning 'as an oxidizing I, agent.

2. Pyrotechniccomposition with fulminating V characteristic comprising.a mixture of zirconium, a perchlorate; andfa color producing ingredient,the perchlorate functioning as an oxidizing agent and the zirconiumbeing comminuted to adegree of coarseness producing stars in the fieldof the flashqeventuating from the detonation of said 3. Pyrotechniccomposition capable of detonatingcomprising a mixture of an elementselected from the following group, zirconium, titanium,

thorium, yttrium, selenium, with an oxidizing agent, said element'beingcomminuted'to a. state of suflicient coarseness to produce stars in theflash.

4., Pyrotechnic composition capable of detonating comprising a mixtureof a fuel element selected 'from the following grou'pf zirconium,titanium,

thorium, yttrium, selenium with a perchlorate and a. color producingagentusedin sumcient proportion to produce a. decided color in theflash,

the fuel element being comminuted to such degree I of coarseness as toproduce stars in the flash.

- JOSEPH'WB. DECKER.

HERBERT c. CLAUSER.

